Chlorinated methylene-bisdimethyl hydantoin



Patented July 16,1946

CHLORINATED METHYLENE-BIS- DIMETHYL HYDANTOIN Arthur 0. Rogers, Lewiston, N. Y., assignor to i E. I. du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application March 27, 1943, Serial No. 480,852

4 Claims.

This invention relates to a new chlorine-containing compound, and to a method by which that compound may be prepared from readily available starting materials. More particularly,

CH3 CH3 The empirical formula is C11H1604N4.

Methylene bis dimethyl hydantoin and methods for preparing it are described and claimed in the copending application of Joseph Frederic Walker, Serial No. 434,436, filed March 12, 1942.

I have now found that certain novel chlorineyielding compounds may be prepared by reacting chlorine with methylene-bis-dimethyl hydantoin in an aqueous solution which is alkaline in reaction. The resulting product, N,N'-dichloro- (methylene-bis-dimethyl hydantoin) is a solid product containing 21.05 per cent of active chlorine. It can be used in place of the hypochlorites or other chlorine-yielding chemicals, and is gener ally less water sensitive than those products. It is less reactive in moist air, and is characterized by low vapor pressure and high molecular weight.

In preparing the new chemical compound, methylene-bis-dimethyl hydantoin is dissolved in an aqueous alkaline solution. The solution may be rendered alkaline by the use of any basic material which does not have an adverse effect in breaking the ring structure of the starting material. We have utilized sodium carbonate with resultant high yields, but other basic materials such as lime, sodium hydroxide, sodium bicarbonate, etc., may also be used.

Gaseous chlorine is now passed into the aqueous alkaline solution containing the dissolved methylene-bis-dimethyl hydantoin. It may be pointed out that complete solution of the entire amount of the methylene-bis-dimethyl hydantoin is not necessary, and the reaction will proceed to completion even when there is present undissolved starting material. The amount of chlorine passed in should be regulated so that two atoms of chlorine are introduced into the methylene-bisdimethyl hydantoin, replacing the two hydrogen atoms attached to the nitrogen atoms. This may involve testing samples of the product from time to time and determining its chlorine content, thereby insuring complete replacement of both hydrogen atoms by chlorine.

When the chlorination is substantially complete the product is filtered off and washed in distilled Water. The filtrate may contain some unconverted starting material, and by passing chlorine into this filtrate additional amounts of the dichloro product may be recovered.

N,N-dichloro (methylene-bis-dimethyl hydantoin) is a distinct chemical compound having the following formula:

The equation representing the chemical reaction which occurs is as follows:

Proof of the structure of the new compound N ,N '-dichloro- (methylene-bis-dimethyl hydantoin) involves first establishing the structure of the methylene-bis-dimethyl hydantoin starting material, and then the point of attachment of the two chlorine atoms introduced. Methylenebis-dimethyl hydantoin is prepared from dimethyl hydantoin in accordance with the method described in the above-identified copending Walker application. Nitrogen determinations according to the Kjeldahl method prove the presence 3 of four nitrogen atoms and confirm the empirical formula C11Hl604N4 for methylene-bis-dimethyl hydantoin. The structural formula of dimethyl hydantoin is of course well established. When two molecules of dimethyl hydantoin are joined by a methylene bridge, in accordance with the process disclosed in said Walker application, in order to produce methylene-bis-dimethyl hydantoin it is necessary first to locate the methylene bridg with reference to the two dimethyl hydantoin molecules joined.

Since only two of the original four NH groups present in the two molecules of dimethy1 hydantoin are available when the methylene-biscompound is later chlorinated, it is evident that the methylene linkage in methylene-bis-dimethyl hydantoin must be between nitrogen atoms. As the compound acts as a weak dibasic acid in the formation of salts. and is soluble in cold sodium hydroxide solution, this confirms the presence of two of the groups CNHC- in which the NH radical is rendered acidic by the presence of the two adjacent carbonyl groups. The acidic characteristic of such compounds is illustrated by the acidic character of phthalimide, for example. If the methylene-bis-dimethyl hydantoin molecule were so constituted that the methylene bridge occurred between the nitrogen atoms of each dimethyl hydantoin ring structure which are positioned between the carbonyl groups, the compound would then not contain any -CNHC- II ll wherefrom it follows that the methylene bridge which connects the nitrogen atoms must be so positioned as to give the compound the structure, CH3 /OH3 /C-N --CH2/NC CH: 0:0 0:0

That the two chlorine atoms introduced are attached to nitrogen is evident since the chlorine is capable of liberating iodine from solutions containing the iodide ion in the proportion of two atoms of iodine per atom of chlorine. This behavior is determinative of N-chloro compounds (N-chloro phthalimide is illustrative) but not of compounds wherein the chlorine is attached to carbon. It is therefore evident that the new distilled water and again filtered.

chemical compound N,N'-dichloromethylene-bisdimethyl hydantoin must have the structural formula given above.

Example An aqueous alkaline solution was prepared by dissolving 560 grams (5.28 mols) of sodium carbonate in 6720 cc. of distilled water. Methylenebis-dimethyl hydantoin in the amount of 450 grams (1.678 mols) was then added, and the mixture heated to 3540 C. in order to secure complete solution. During this period distilled water in the additional amount of 200 to 300 cc. was added.

The solution was filtered and placed in a reaction flask. The temperature was maintained at 35-40 C. and, chlorine gas was passed in. At the end of one hour the supply of gas was cut ofi. and the precipitated product removed by filtration. This product was washed with. 2-3 liters of The two filtrates were then brought together and further amounts of chlorine passed thereinto for about fifteen minutes. This resulted in the formation of an additional amount of product which precipitated in the liquid, this product being removed and washed as before.

The yield of dichloro-(methylene-bis-dimethyl hydantoin) was 526 grams or 92.7% of the theoretical. The product had an active chlorine content of 20.00% as determined by iodometric titration (96% of theoretical), and a melting point of 202-206 C.

Dichloromethylene-bis-dimethyl hyda-ntoin) is a white powdery material having a characteristic odor. It is non-combustible and nonexplosive, but decomposes at 250 C. with the evolution of chlorine. Its solubilities in various solvents at various temperatures are as follows:

23 3??? Temperature Kerosene 1 3? Methylene chloride g Perchlorethylene 0. 015 26 Sym.-dichlorethane 0. 415 26 Carbon tetrachloride 0. 03 26 Sym.-tetrachloretl1ane. 2. 23 26 Toluene 0.161 26 Methyl alcohol 0. 186 26 Absolute ethyl ale 0. 093 2G l,4- dioxane 4. 2 25 l-mtropropane 1. 39 25 Oyclohexanone... 3. 08 25 Nitrobenzene. 0. 88 25 Ethyl acetate l 1. 13 25 The compound hydrolyzes in water yielding a solution containing from 28 to 30 parts per million of available chlorine. This solution is useful as an antiseptic and germicidal agent, and for various bleaching and decolorizing purposes. Solutions in inert solvents may be used for impregnating cloth or other fibrous material, or for other purposes.

I claim:

1. N,N'-dichloro'-(methylene-bis-dimethyl hydantoin) having the formula:

2. The method of preparing N,N-dichloro- (methylene-bis-dimethyl hydantoin) having the CH! formula: ON-CH2--N( JCHe C=NCH:- N-C 5 OEh l c=0 o=o i cm )1 $1 0= 4. A white powdery material which melts at 1 1 a. temperature between 202 C. and 206 C., decomposes at a temperature of 250 C., hydrolyzes which cornpnses reactmg ch1 orine wlth methyl- 10 in Water to yield a Solution contaimng free ch1o ene-bis-d1methy1 hydantom 1n a dilute aqueous rim and has the empirical formula alkaline medium.

3'. A white powdery material having the for- C11H144N4Ch mula: ARTHUR 0. ROGERS. 

